Draft Genome Sequence of the Feruloyl Esterase-Producing Strain Lactobacillus fermentum CRL1446, a Probiotic for Malnutrition.

We report here the draft genome sequence of Lactobacillus fermentum CRL1446 (2,148,781 bp, 51.4% G+C content). This strain exhibits feruloyl esterase activity and important technological and probiotic properties. Because of its proven beneficial effects in vivo, it represents an interesting candidate for the development of functional foods or pharmabiotics for malnutrition.

Lactobacillus fermentum CRL1446 Ameliorates Oxidative and Metabolic Parameters by Increasing Intestinal Feruloyl Esterase Activity and Modulating Microbiota in Caloric-Restricted Mice.

The purpose of this study was to determine whether the administration of the feruloyl esterase (FE)-producing strain Lactobacillus fermentum CRL1446 enhances metabolic and oxidative parameters in caloric-restricted (CR) mice. Balb/c male mice were divided into ad libitum fed Group (ALF Group), CR diet Group (CR Group) and CR diet plus L. fermentum Group (CR-Lf Group). CR diet was administered during 45 days and CRL1446 strain was given in the dose of 108 cells/mL/day/mouse. FE activity was determined in intestinal mucosa and content at Day 1, 20 and 45. Triglyceride, total cholesterol, glucose, thiobarbituric acid reactive substances (TBARS) levels and glutathione reductase activity were determined in plasma. Gut microbiota was evaluated by high-throughput sequencing of 16S rRNA gene amplicons. At Day 45, total intestinal FE activity in CR-Lf Group was higher (p = 0.020) than in CR and ALF groups and an improvement in both metabolic (reductions in triglyceride (p = 0.0025), total cholesterol (p = 0.005) and glucose (p < 0.0001) levels) and oxidative (decrease of TBARS levels and increase of plasmatic glutathione reductase activity (p = 0.006)) parameters was observed, compared to ALF Group. CR diet increased abundance of Bacteroidetes and CRL1446 administration increased abundance of Bifidobacterium and Lactobacillus genus. L. fermentun CRL1446 exerted a bifidogenic effect under CR conditions.

Contribution of lactic acid bacteria esterases to the release of fatty acids in miniature ewe's milk cheese models.

The present work evaluates the contribution of esterase activities of lactic acid bacteria isolated from ewe's dairy products to the release of free fatty acids (FFA) in ewe's milk cheese models. At 60 days of ripening, single-strain cheeses Ov 409 and Ov 421 showed high levels of total FFA (3075 and 2494.62 mg/kg, respectively). Cheeses Ov 227-Ov 409 and Ov 421-Ov 409 presented high percentages of short-chain fatty acids (SCFA). The highest levels of volatile free fatty acids (VFFA) were detected in cheeses Ov 409, Ov 421-Ov 409, and Ov 421-Ov 227. Studies on esterase activities showed that these strains hydrolyzed alpha-naphthyl derivatives of fatty acids from C2 to C6, mainly associated with the wall-membrane fraction. The results showed that the strains studied contributed to the release of FFA during ripening of ewe's milk cheese models. The increase of SCFA throughout ripening involves the action of esterases of starter strains.

Citrate metabolism by Enterococcus faecium and Enterococcus durans isolated from goat's and ewe's milk: influence of glucose and lactose.

Citrate metabolism by Enterococcus faecium ET C9 and Enterococcus durans Ov 421 was studied as sole energy source and in presence of glucose or lactose. Both strains utilized citrate as the sole energy source. Enterococcus faecium ET C9 showed diauxic growth in the presence of a limiting concentration of glucose. Neither strain used citrate until glucose was fully metabolized. The strains showed co-metabolism of citrate and lactose. Lactate, acetate, formate, and flavour compounds (diacetyl, acetoin, and 2,3-butanediol) were detected in both strains. The highest production of flavour compounds was detected during growth of E. durans Ov 421 in media supplemented with citrate-glucose and citrate-lactose. Citrate lyase was inducible in both strains. Acetate kinase activities presented the highest values in LAPTc medium, with E. faecium ET C9 displaying a specific activity 2.4-fold higher than E. durans. The highest levels of alpha-acetolactate synthase specific activity were detected in E. durans grown in LAPTc+g, in accordance with the maximum production of flavour compounds detected in this medium. Diacetyl and acetoinreductases displayed lower specific activity values in the presence of citrate. Enterococcus faecium and E. durans displayed citrate lyase, acetate kinase, alpha-acetolactate synthase, and diacetyl and acetoin reductase activities. These enzymes are necessary for conversion of citrate to flavour compounds that are important in fermented dairy products.